DESCRIPTION: Our study will integrate existing and new prospectively-collected data to test the hypothesis that better nutrition during early childhood enhances adult productivity through its beneficial effects on the accumulation of human capital. The population to be studied was born in four villages in Guatemala. Early childhood data come from a well-known longitudinal study, rich in data about the home environment, growth, cognitive development, diet and morbidity, which assessed the impact of improved nutrition, achieved through a controlled supplementation trial conducted between 1969 and 1977, on child growth and development. A follow-up study in 1988-89 assessed human capital formation and productivity at age 11 to 26 years. Analyses of these data led us to conclude that better nutrition in early childhood improved human capital; this conclusion was necessarily tentative as less than half of the cohort had reached adulthood. Moreover, we were unable to test relationships between nutrition in early childhood and adult productivity, because only a fraction of the sample had married or settled in an occupation with steady employment and/or were independent of the parental household. We, therefore, propose to collect a new round of data in 2002, when the cohort will be 25 to 40 years of age. Cohort members will be traced and studied whether they still live in their birth village or have migrated. Spouses will also be studied. Our study will be the first to link prospectively collected data on early childhood nutrition to economic data (including on physical health and mental capital, family formation, migration and occupation, and agricultural and non-agricultural economic productivity) in mature adults, and, thus, the first to be capable of validly testing these relationships. Our study team includes accomplished researchers in anthropology, economics, nutrition, epidemiology, biostatistics and medicine, providing broad multidisciplinary experience. Three institutions, each with strong and complementary research traditions and resources participate as equal partners: the Rollins School of Public Health of Emory University, the International Food Policy Research Institute and the Institute of Nutrition of Central America and Panama (INCAP). The three participating institutions have a successful history of previous collaboration in complex field studies and other research.